The present invention is directed to an impact and/or vibration absorbent material and to various impact and/or vibration protective articles that incorporate such a material. A testing apparatus that is particularly well-suited for determining the impact force absorption characteristics of such a material is also disclosed.
Exposure of the human body to repeated impact and/or vibration is a known problem. Such exposure can occur in various settings: both occupational and recreational.
It is known, for example, that extended exposure of the human body to vibration can lead to vascular, neurological and musculoskeletal disorders. The source of such vibration is commonly some type of mechanical device, such as a hand-held vibrating tool. In the case of exposure to hand-held vibrating tools, resultant disorders typically manifest in the body's upper limbs—such as in the form of carpal tunnel syndrome, for example.
Similar problems may also result from repeatedly impacting an object with the hand. There are many situations, particularly occupational situations, where a person's hand is effectively used as a tool to impact another object. For example, in certain automotive manufacturing operations, the hand can frequently be used to install fasteners or to set the position of one assembly component to another. In such a situation, it is desirable to transmit as much of the hand-generated impact force as possible to the impacted object, while simultaneously protecting the hand from impact related injuries.
Also problematic is what may be referred to as whole-body vibration, such as may be transmitted through the seat of an industrial vehicle. A multiplicity of vehicles may transmit such vibration: from large outdoor earth-moving equipment to commonly used forklifts and tow motors, for example. Rather than causing a problem with a particular limb or limbs, however, whole body vibration commonly results in spinal system disorders.
The human body, or particular portions thereof, may also be exposed to undesirable impact and/or vibration in a recreational setting. For example, it is known that long term participation in certain racquet sports may lead to similar problems. Interestingly, it has also been found that such problems may plague cyclists due to the persistent pressure put on the nerves of the hand by the handlebars of a bicycle (or motorcycle), as well as the transmission of shock and vibration therethrough. Certainly, a person's shoes can also transmit shock and/or vibration to the feet during walking, running, hiking, climbing, or other activities.
Various types of protective equipment have been produced in an effort to combat the aforementioned problems. Of particular interest are gloves that have been designed to reduce the amount of impact and/or vibration force transmitted to the hand when using devices such as hand-held power (vibrating) tools, or when using the hand as an impact tool. Other articles have also been developed in this pursuit, including, for example, shoe soles and shoe inserts. These articles may make use of different material compositions, multiple air bladders, and/or various other designs and techniques to achieve a reduction in impact and/or vibration transmission.
However, Applicants have discovered that, at least with respect to hand protection, each of the known products still transmits a significant amount of impact and/or vibration to the wearer's hand. Consequently, any improvement in impact and/or vibration absorbent hand protection is highly desirable. An impact and/or vibration absorbent material of the present invention and a protective impact glove made therefrom can provide such improvements.